Investigation of the relationship between quantitative and qualitative characteristics with yield and yield components in cotton cultivars

Cotton (Gossypium hirsutum) is an important industrial crop where increasing fiber yield is one of the main breeding goals. Several traits are considered in plant breeding, most of which are highly correlated with each other and with yield. This study was conducted to investigate the correlation and path coefficient analysis (causal relationship) between traits and yield components in cotton. The aim of this study was to identify the traits that affect yield, to better understand the relationship between the traits, and to establish a relationship between yield and its components in new cotton varieties.

Seeds from seven of the best cotton hybrids and commercial varieties (as controls) were planted in a four-replication randomized block experiment at the Hashemabad Research Station. Plant height, length and number of unipodial branches, length and number of sympodal branches, number of bolls per plant, boll weight, cotton seed and early maturity were examined. After analysis of variance and comparison of mean traits using Duncan’s method, the correlation coefficient between traits was calculated and stepwise regression analysis and path coefficient analysis were used to identify and determine the traits affecting performance.

The results in terms of quantitative traits showed that the Golestan variety had good quantitative and qualitative traits and gave a high yield. In addition, the SB26 variety was superior to the other varieties in terms of lint content and fiber fineness. The results of the simple correlation between the traits showed that the performance showed a positive and significant correlation with the number of sympodial branches and the number of bolls (0.7), but showed no significant correlation with other traits. The results of the stepwise regression for yield showed that boll number, boll weight and number of sympodial branches were the most important characteristics in determining yield and explained 83.8% of the variance in yield. In addition, the cluster analysis used to group the varieties divided them into 4 separate groups.

In general, the results of the mean comparison of the examined varieties showed that the genotypes TJ82 and SB7 can be proposed for future breeding projects due to a number of characteristics, although there is no significant difference between the varieties in terms of yield of traits, such as e.g. B. a yield of more than 3 tons. In addition, the early maturity, the high proportion of straw and fiber fins makes the SB26 genotype an attractive genotype as an entry genotype for future breeding projects.